13 October 2015

From time to time we will have customers that report "flashing" or brief periods of interruption of light output or stuck lights/pixels on E1.31 controllers they are using. While we can't provide a specific answer to the question because there are just too many variables, this article hopefully can provide you some concrete troubleshooting steps to find a resolution to the issue.

E1.31 or sACN (or also Artnet) is just but one part of a complex stack of interconnected systems that take the output from your sequencing application to your controller, so let's look at each layer in this stack and talk about possible causes and troubleshooting steps you can take to eliminate the problem.

Lights (Pixels)

We are starting at the very bottom of this stack - lights. Most E1.31 controllers have built-in test functions in the firmware of the controller that will output a test pattern (for AlphaPix controllers see this video) that can be invoked via a button or buttons on the controller. Why this is useful is to isolate the two major parts of the stack - the controller from PC and to determine if the problem is in the hardware. Start the hardware test function, ideally with a "full white" output and watch for any signs of the flashing. If flashing occurs at the hardware level - most likely the problem is controller, lighs or power based - look at the following as possible problem sources:

If flashing occurs only when a lot of lights or when full white or other high draw output is happening but the flashing does not occur with a single color, the likely cause could be insufficient power for the number of lights running.

In minor cases of under-powered lights, individual pixels can receive insufficient power and once they drop below a certain voltage, they fail to function. This most often will show up at the end of a string of lights.

In major cases of under-powered lights, the power supply will cut off due to an over-current situation, usually for a few seconds at a time. All lights will turn off that are connected to the power supply.

If you suspect any of the above, put the lights on all-white output on all pixels and then using a multi-meter, measure the voltage at the end of the string of pixels. If you notice large drops, there may be a power issue.

Networking

Because E1.31 controllers are network devices on an Ethernet network, it is possible the network itself is inducing delays or lost packets of data. Areas to consider are:

If using ANY wireless - remove the wireless components (bridges, extenders, access points, etc) and move back to a wired connection for testing to ensure that the wireless network is not the source of the problem. On a secondary note - we do not recommend using wireless networks unless there is no good alternative to good ol' CAT5 cable. Wireless can induce delays, suffer higher packet loss and be subject to other interference on the network, more so than an wired network.

If the PC you are using has more than one interface / network, such as a wireless interface plus a wired interface, disable all other Ethernet interfaces on the PC. We have seen cases were routing problems within the PC resulted in delays of traffic going to the network where the E1.31 controller was located.

If the controller is not directly connected to the PC - such as hooked to a local router/switch/hub - where possible, hook the cable directly from the PC's Ethernet network plug directly to the plug of the E1.31 controller.

Try running a PING to the controller continuously to confirm that there are not lost packets.

PC / OS

This area is where we see a fair amount of the problems with random flashing, mainly with one thing - firewall applications. Most PC's today have a firewall (Modern Windows PC's all have one) and often they have third party firewalls such as Symantec or AVG. These applications constantly monitor or "inspect traffic" going out of and into your PC and when they sense something is dangerous - rightfully or not, they block that traffic or do a "deep inspection" of the data in an effort to determine if it is dangerous, sometimes inducing delays. The problem with this is that if an application is "tinkering" or outright blocking the traffic, this can result in delays in the data arriving or arriving out of order, resulting in random output which could be seen as blinking. When troubleshooting, we recommend disabling your firewall - most have a "disable for 15 minutes" function that turns off the blocking allowing you to take the firewall out of the "loop".

A note for customers using on PC based items such as the FPP - if you are experiencing problems when sourcing data from the FPP, switch to a PC and test from there.

A note for customers using virtualized environments such as Window in a Mac - we recommend testing from a dedicated PC.

Additional E.131 Applications

It is common for people sequencing E1.31 controllers to have several E1.31 based applications on their PC - applications like xLights and LOR. What most people don't realise is that these applications, even when not running a sequence or test, are outputting E1.31 data to the controller. The primary application we see the most issues with is LOR's 'Control Panel', which if configured and open is always outputting E1.31 data even with the LOR Sequence Editor closed. So, if you are using more than one application, make sure to close or "unload" the other application so that it doesn't step on the data or send two streams of data to the controller, causing confusion to the controller, at the same time. To unload LOR, right click the Light Bulb icon in the system tray, then select "Unload Light-o-Rama".

Sequencing Application

The final and highest layer in the stack is of course - the sequencing application. This is where the data originates from to make your show. There can be a wide range of possible issues to consider with sequencing applications:

Application flaw - Some open source applications are written with updates on a weekly basis and this can induce bugs that result in un-predictable output on something that on screen appears to be fine. If a sequence worked last week and now exhibits a problem and the hardware configuration has not changed, you may wish to roll back to the old version of the application and re-test.

Incorrectly configured sequence - If you experience a problem with a sequence, "fall back" and create a new, simple sequence that contains no imported or migrated information and only a limited amount of sequencing necessary to replicate the problem being experienced.

Sequence overloading PC - Since sequencing applications and displays are now in the tens of thousands of channels, it is possible that your sequencing application is generating more data than can be properly output to your network going to the E1.31 controller(s) from the PC you are using. Falling back to a simple test sequence or removing controllers from a sequence can help to narrow this problem down.

Where possible, you may wish to try using a completely different application for E1.31 data output for testing. Our 100% flaw free and go-to application after all these years is still xLights 2012b - no, not the new "xLights/Nutcracker" 4.x but the older, simpler and super clean application from years back. The 2012b version of the application can be found on this site: http://sourceforge.net/projects/xlights/ for free download and here is a video that shows how to use it for testing:

If your problem goes away with xLights or another application but still occurs in your original sequencing application, likely the problem is with that application.

Last Ditch...

In some very rare cases we at HolidayCoro need to determine is this a controller and/or network issue or a PC/Software issue, we have to pull out WireShark. WireShark is a free application that allows you to look directly at the data being sent to the network and then to the E1.31 controller. From here you can see any mal-formed packets or other errors going to the controller. With enough effort, you can then compare the packets and see if the problem is controller or software. In one case where our AlphaPix controller was blinking with LOR software while the LOR control panel was running, this was necessary and shows the value of such low level troubleshooting:

We should note that it is exceeding rare to have to use tools like this and most of the time your vendor should be able to assist you prior to getting to this level.

Firmware

While the E1.31 protocol is a fairly simple thing, it is always possible that there is a flaw in the vendor's firmware. If you suspect this, first update the the latest version of the firmware provided by the vendor, then if that does not resolve the problem, try general troubleshooting such as moving around outputs - switching universes mapped to different outputs to see if the problem "follows" the output or the universe.

If you suspect a controller issue, we recommend providing your vendor with the following:

A detailed list of steps taken to narrow the problem down. Where possible, always use specific references such as "output 1" instead of "the output".

Provide a clear overview of how the controller is configured (channels, universes, etc) in addition to what items are connected to the controller (pixel counts, etc)

Provide a copy of the sequences used to test and reproduce the output

Provide details of your network configuration

Remember, the vendor has zero understanding of your specific setup and testing that has been completed and for them to provide a solution in all but the most basic of situations, detailed information will be required.

Conclusion

We won't kid you - E1.31 while itself being quite simple, is made much, much more complex due to the large number of variables and layers involved with getting data from one end of the stack to the other. When troubleshooting these problems, it always helps to start at the basics, then work your way up from there. Never assume anything is "ok" until it proves to you through testing that it is working.

15 January 2015

HolidayCoro receives a large number of questions each year from people that just don't know exactly where to start with the design of an RGB element (House Outline, MegaTree, arches, etc) and we can completely understand how overwhelming the process can be when just starting out. After working with so many customers, we have come to see a fairly standard process emerge that can bring most customers through from "How do I" to "I did it!". Please note that due to the complexity involved with each project, this article, as detailed as it is, does not contain 100% of the technical information needed for your project. Please consult with your vendor for application specific advice.

Here is a broad overview of how that process works and listed below is a more detailed breakdown of each major task and what you should consider at each decision point.

(Click picture to enlarge)

Let's start with a few questions that you are likely to ask yourself as you read this:

I don't want to solder

While there are some elements that lend themselves to full plug-n-play solutions, such as MegaTrees, other elements such as a house outline are 100% custom and since each house and design requirement is unique, it is almost a sure thing that you'll need to customize the hardware you purchase to meet your specific needs and this most often means - soldering and building items yourself. So, consider this factor when picking the project you want to build.

HolidayCoro also offers a number of products with strip and nodes (see below for what these are) that feature pre-soldered and attached waterproof connections.

What is a Pixel?

A Smart RGB pixel is a single light or a small group of lights (each themselves comprised of an Red, Green and Blue light), usually never more than 4 total lights, that are individually controlled much like a "pixel" in your computer screen. That pixel can be any color (hundreds to millions) and can be directly controlled separate of the other pixels. What a pixel is NOT is a full string of lights that all turn the same color, even if they are RGB, at the same time. Pixels are ALWAYS individually controlled (within a small grouping of lights). There is no such item as a "Dumb Pixel", all pixels are "Smart".

You are talking only about "smart" or "intelligent" pixels but what about dumb RGB?

A number of years ago, before the advent of super-cheap pixels and the availability of high pixel count controllers (E1.31 controllers), dumb was a reasonable direction to consider over smart pixels. Fast forward to 2016, with prices for smart pixels and controllers generally running 20-30% more over dumb, it now makes little sense to go with dumb on most larger elements (house outlines, MegaTrees, arches) over smart pixels. That said, there are still places dumb RGB makes sense but that area is growing smaller everyday.

What voltage should I use for my RGB lights?

The two most common RGB light voltages are 5v and 12v DC. See our Knowledge Base article about the pro's and con's of using each voltage type and some common rules of tumb for each type of project and light type.

What pixel controller do I need for my project?

It is common for people to be concerned about controller selection early on in a project and what we find is - it just doesn't matter. We say that you don't pick a controller, the controller picks you and that is because when you've properly defined your project as to design, power and pixel count, the possible choices of pixel controllers is usually pretty narrow and obvious.

I don't know anything about DMX - is this going to be hard?

If you are currently an LOR customer and you worry about "learning" DMX, it isn't hard at all. There are only two things to learn about DMX:

A DMX Universe has up to 512 channels (or 170 pixels, each with 3 DMX channels).

A controller simply has a DMX start address for something (such as pixels) hooked up to it, so if you have a 24 channel controller and you set the controller up as DMX channel 1 in universe 1, the controller will use DMX channels 1-24.

That's how simple it is!

Can I hook up (daisy chain) E1.31 (AlphaPix controllers) with my LOR Controllers?

No - E1.31 (DMX over Ethernet) is a completely different signalling system than LOR controllers which use an older technology called RS-485 - not Ethernet which is used in E1.31. To split the signal to multiple E1.31 controllers, use a cheap network switch. For a complete list of all possible inter-operational solutions with LOR and DMX networks, see our Knowledge Base.

PICK A SINGLE PROJECT

It can be a bit overwhelming to see YouTube videos of amazing RGB displays and think - how do I get there? Well, it starts with narrowing your choice to a single project or "element". While it is important to think of the overall display design, such as where you might put arches, or a singing character or a MegaTree, once you decide on a given element, then you need to narrow your project to just that element. Most often controllers, power and other factors are centralized to that specific element and thus stand alone from other elements in the display, so, building one element at a time most often makes the most sense.

There are many different elements you can pick from but the three most common RGB elements are:

Can be extremely simple if purchased as a complete package that is plug-n-play (up to including pre-sequenced songs) or moderately complex if completely custom. The most complex part is often the mounting system for the lights and sequencing, not the lights and controllers.

Expect to spend 6 to 60+ hours building depending on if it is plug-n-play or custom

Picking a single project will allow you to focus and get a win and make future RGB based projects much easier.

DETERMINE THE DESIGN

Once you've narrowed your choice to a selected element you want to build, you'll want to determine the specific design you want that element to have. Design factors of some of the common elements include:

Without a clear idea of the design, it is nearly impossible to properly determine what should come in the next steps. Note that while there are some common questions listed above that you should be asking yourself, there are always many more that are specific your location, budget and even motivation. Also note that at this point it can be hard to determine the cost of an element until the entire process is completed, so you may need to go through the entire process of design and specification, then return back to either scale up or down a project based on cost.

DETERMINE THE LIGHT TYPE

Asian Country Style Pixel Node Channel Letter Sign

Now that we have the question of where we should put the lights in or on our element, we need to determine the actual type of light we want to use to reach our design goal. There are a number of different physical formats of RGB pixel lights on the market today, the major groups include:

This type of pixel is native to the sign industry in Asia. As where in the US we install LED lights in a channel letter sign and face the sign with acrylic, in Asia they often will use sheet metal instead of acrylic and fill this area with 12mm holes in which these nodes are mounted. The holiday light community has adopted these nodes for their own uses outside of being mounted into a sign blank.

Common traits include: Flexible (also available in a rigid format but that is uncommon in holiday lighting since we mount it to a substrate), usually sold in meter long lengths coiled into "rolls". Waterproof and non-waterproof "boots" - generally you can ignore "IP" ratings as they are often fake or misleading.

Pixel strip is normally defined by the meter length. As such, you usually see pixel strip listed as: 30/10 or 30 LED/s per meter, 10 IC/s per meter. These numbers define the strip construction and by these two major numbers:

LEDs per Meter (LEDs/m) - For a given one meter (39 inches) length of strip, this says how many LEDs it contains. For RGB strip, that LED is 5mm by 5mm in size, (most often called 5050's) each one which contains all three (RGB) LEDs. So, 30 LED/m strip will contain thirty, 5050 LEDs, each which contains three individual color LEDS. Technically, this would mean that a 1 meter length section of 30LED/m would contain 90 individual LED lights.

ICs per Meter - This defines how many IC's or integrated circuits are located in a single meter of strip. A much easier way to think of this is "Pixels per Meter" instead since what it really means is how many, individual lights or small groupings of lights can be individually controlled. A common strip might have "10 ICs/m", so this means that in the 1 meter length there are 10 "sections" or pixels that can be controlled. When the number of IC's is divided into the number of LEDs per meter, you know how many individual lights make up a group, if any. For 30/10 strip, this would mean that over the 30 LEDs in that meter, every 3 LEDs makes up one "pixel".

When the LEDs and the ICs become the same number, such as 30/30 or 60/60, that means that each LED is directly controlled, not a group of LEDs.

Voltage - For strip, the absolute most common voltage is 12 volts. It just works too well not to recommend it for the small price difference over 5 volts. When you should be using 5 volt strip, you'll know.

Always purchase strip in a silicon "boot", we recommend without "injection" for easier soldering and repairs. Strips with "silicon injection" are not necessarily stronger.

You might noticed that often 12v strips will come with 3 LEDs per pixel and there is a good reason for this - it allows the power to be run in series instead of parallel, improving the power efficiency of the strip. Strips with 30/30 or 60/60 often have to have "buck" converters to reduce the voltage from 12v to 5v throughout the strip to accomplish the same thing and as a result, are more expensive - they also have limits on where they can be cut.

Common traits include: Many different types of RGB LEDS (5mm, 12mm, 5050, etc) mounted in a self contained housing of either plastic or metal.

Modules are often variations of strip or modules. For example, a rectangle pixel module (see below) often is just a single pixel with the same type of LEDs (5050) and the same format of 3 LEDs but instead of being in a flexible strip, are instead mounted into a rigid housing with wire connecting the modules together.

Modules are typically used when pixels need to be mounted in many different directions, such as on curves, stars or in-fill

Common traits include: A diffused cover of either milky or clear plastic is placed over a variety of LED types (8mm and 5050's are common).

These are designed to mimic the look of "traditional" C7 or C7 bulbs.

Typically come with wire separating each pixel of a few inches to a foot.

As these bulbs are not "normal" C7 or C9 bulbs, mounting them can be fairly different than typically done with standard "legacy" bulbs.

Here are some samples of bulbs below:

If you've never seen these types of lights, you might want order a sample kit that contains a few of each type of pixel.

DETERMINE MOUNTING LOCATION AND METHOD

The process of determining how you mount the selected light is sometimes a process of refinement. You may need to select a light type (from above) but also at the same time consider how that light will be mounted. Nearly all pixel types need to be mounted to some sort of substrate or mounting system. That can be many types of items, from PVC pipe, EMT pipe, rope, banding, custom mounting adapters, steel, plastic sheet, coro and many others. Why do pixels require this mounting? Several reasons - the first is that pixels are a bit more fragile than traditional lights and the second is that pixels, in most cases, need to be very accurately aligned and spaced to ensure a consistent appearance. Remember, each of these lights (or group of lights) is directly referenced in "space" within your sequencing application and thus they need to be in a predictable location and pattern.

An important factor to consider when selecting a mounting location is one thing - your viewer and audience. If your display is viewed from the road, stand in the road at the same height a typical viewer would see your display. If your display has lots of foot traffic, look at the display from all the possible angles your viewer would be at. Placing elements or lights that overlap one another or are only partially visible will distract from the overall effectiveness of your display (e.g. - MegaTree in front of a house outline). A general rule of thumb is to place larger items to the back of the display (megatrees) and smaller items towards the front (arches, mini-trees).

Start by selecting the mounting location - this will vary based on the element itself but will be defined by the pixel type you've selected. Here are some general areas to consider for several common projects:

RGB Pixel House Outline

Make sure that all outlines can be seen from the normal viewing point of your audience.

On front of fascia - Consider issues such as snow or ice obstruction, daytime "look" and if the mounting system will be left up year round, consider how that will look when the lights are removed leaving the mounting hooks / clips / etc.

Under fascia or soffit - A preferred mounting location when used with year-round installations. Be aware of the reflection of light off the wall and soffit as this can create undesired "wall washing".

Doors / Windows / Garage

Roof Line - Make that your audience can actually see the entire roof line.

The first major factor in a MegaTree to consider is the viewing angle and how many degrees your MegaTree needs to be to be fully visible (assuming this is what you want) at all time. A typical tree will be 180 degrees since all pixels will be pointing away from the center of the tree and most trees because of their size are located at the back of a display, it doesn't make sense to have lights on the back of the tree.

A RGB Pixel MegaTree is just a large rectangle matrix of pixels, instead just wrapped in a cone. As such, you need to mount these pixels consistently with vertical and horizontal spacing. Pixels can't just be left "dangling" without support or directional assistance.

The two most common pixel types are strip and nodes.

Strip - Usually limited to 16 ft and is most often supported with EMT or PVC pipe and using zip ties or velcro to attach the strip to the pipe. Rarely used in 20 ft + MegaTrees.

Nodes - Sizes can be 40 feet + usually without issue. Products like our PixNode Strip(tm) can be used for mounting pixels. Also consider how the node mounting system will work with your support system. You may wish to check out the HolidayCoro QuickTree(tm) Pixel MegaTree mounting system.

Rebar (usually 24" to 36" long) put into the ground at an angle and the PVC pipe slid over the top of the rebar.

Some people will use diffusers of plastic or other materials to create a more blended color output also but this is not required.

An important part is to think through the entire life cycle when designing your mounting system - consider not only the cost and time to build but also how hard it will be to install, repair if needed and remove from your display. Also consider storage in the off season.

DETERMINE HOW MANY LIGHTS ARE NEEDED

At this point you should now know what type of light and how you will be mounting that light but a still more important decision - how many of those lights, needs to be determined. There are some pretty logical factors to consider when selecting your lights, so let's start with an analogy of two other items that use pixels in your daily life and how they can be used to help determine how many lights we might need.

Density vs. Distance

Both the TV in your home and the monitor on your computer, laptop, tablet or phone have one purpose - to convey information to you through a grid of individually controlled RGB pixels and there are some very close associations between those devices and a pixel based element for a holiday display.Try this - go up to your 55"+ flat screen TV and look closely, at about 2 feet or so from the TV and you'll likely be able to make out the individual pixels and the resulting picture is coarse and grainy but if you stand back to a more normal viewing distance of say 15 feet, you just see a nice smooth picture without a hint of the coarseness.

Now go up to your computer monitor and from the same two foot distance, look for the pixels. With any modern monitor you won't see the pixels, just like you can't see the pixels on your 55" flat screen from 15 feet away. Each monitor might have the same number of pixels but what matters is the density (screen size in this case) of those pixels in relationship to the viewing distance.What this shows us is that there is a relationship between the spacing of the pixels and the viewing distance from the pixels themselves and RGB pixels used in holiday displays are no different. Listed below are some general guidelines on the types of pixels, their density and how far is a recommended distance to view them:

Pixel Type

Recommended Viewing Distance

8mm Node - 1" Center to Center Spacing

10 to 50 Feet

8mm Node - 2" Center to Center Spacing

20 to 80 Feet

8mm Node - 3" Center to Center Spacing

60 to 120 Feet

60/60 Strip

5 to 40 Feet

60/20 Strip

10 to 60 Feet

48/16 Strip

15 to 80 Feet

30/30 Strip

15 to 60 Feet

30/10 Strip

30 to 170 Feet

So you might ask your self - well, why wouldn't I want more pixels - won't it make my display look better? There are a variety of factors at play here:

More pixels doesn't equal better quality at certain distances - For example, a common mistake is that people will want to use 60/60 strip to outline a house with a viewing distance of 150 feet or more. At that distance it just isn't possible for normal people to see the individual pixels.

More pixels is just more channels - For every pixel you add, it adds three additional channels. While that might not sound bad, going from a common 30/10 strip to a 60/60 strip on a house outline will result in five time more channels. Those channels then add up to more work for the sequencing application to process, more network data, larger sequence files with larger file sizes and even if you surpass the limits on your controllers channel count - more controllers and all for what? Nothing that the viewer could see as a difference.

More pixels, is more lights, is more power - As you add more pixels, normally you are a adding more lights also for each pixel and this of course increases the overall amount of power. Increasing light counts increases all kinds of issues - larger gauge wires, more power injection points, more power supplies, more housings and often, more controllers and more money. Again, unless the viewer could actually make use of those pixels, it was all for nothing. On a side note - yes, there could be cases where you want a very high level of light output and putting greater density is one way to do that but keep in mind that the way the human eye sees light isn't linear - so doubling the number of lights won't anywhere near double the light a person "sees". This is the same phenomenon where you can see a red stop light at 12 midnight nearly as well as you can during the brightest part of the day - your eye and brain moderate the amount of light you "see".

Color mixing - Let's use an example of two pixel strips, both viewed from a distance of 75 feet, a common viewing distance for holiday displays. One strip is 30/10 which means there is one pixel with three LEDs every 4 inches. The other strip is 60/60 which means that there is one pixel every .65 inch. Let's then turn on each alternating pixel to red, green, red, green and so on. When viewed on the 30/10 strip at the 75 foot distance, you are going to see the individual pixels, each 4" long and each pixel will be a distinct color with very little color mixing - it will look like what you expected when you sequenced it. Now if we view the 60/60 strip, with their .65" spaced pixels, you likely aren't going to get clean red and green alternating colors but instead you are going to get a muted mix of colors mostly as a yellow color. What happened here? The strip itself was red, green, etc but since the pixels were so close and the viewer so far away, the colors started to mix when seen by the viewer. So, as you can see, more isn't always better and can even result in negative results.

The take-away here is that you should select a pixel and pixel density that is relevant to your display. Keep in mind that some pixel format's pixel density can be adjusted, such as bulbs or nodes but others density is completely fixed, such as with strip.

CALCULATE POWER AND PIXEL COUNTS

We are entering the final stretch and we'll need to take off our design hat and put on our math hat so we can determine how many pixels we will end up with and how much power it will take to run all those pixels. First you need to start with pixel counts.

For pixels with a fixed distance, this is easy - you just take your distances and divide in the number of pixels and you get the resulting number of pixels in a given distance. For example, if we have a house outline that has a section that is 20 feet long and we want to use 30/10 pixels strip which has one pixel every 4 inches, we end up with the following:

20 ft * 12 = 240 inches over the length

240 inches / 4 inch pixels = 60 pixels over the 20 ft length

Check with your vendor for specific spacing amounts. Most pixels will have the following specs:

Minimum Spacing - This is the closest two pixels can be installed, For a "bullet" pixel node it might be about 1.5 inches from center to center. For other pixels there is no adjustment possible, such as with pixel strip which is fixed in spacing.

Maximum Spacing - This is the furthest distance two pixels can be installed apart and the usual limit is based on the length of the wire. Be careful about "spacing" or "wire" lengths listed by vendors, for example, a pixel node might be listed as 3" spacing but when installed, only have 2.5" spacing. Make sure to confirm center to center spacing, not just the distance of the wire that was used to assemble the pixels. Again, some pixels such as strip are fixed in spacing.

Maximum Gaps - Keep in mind that with pixels, there is a limit to the distance that can be spanned between them or from the controller to the first pixel. This limit varies based on a large number of factors but a "safe" number is usually 15 feet with 20 feet often being possible. If you need to go longer between pixels, you'll need to setup "null" or "ghost" pixels that serve only one purpose - to repeat the data from one pixel to another but are not intended to be used for light output.

We would recommend using a spreadsheet to perform your calculations, such as the one available in the House Outline blog post or one of your own design. Along with pixel count calculations, it can also be useful for keeping track of channels and assignments to those channels.

Now that you have the actual number of pixels for the project calculated, you are able to calculate the power requirements. I will caution this is more an art than what should be a science because of the huge number of factors that come into play, including:

Accuracy of the posted pixel vendor specifications - Even a difference of a new milliamps of power when multiplied over a few thousand pixels can add up to large differences. Please note that Chinese specs on items purchased directly out of China are notoriously incorrect.

Accuracy of the actual item purchase - It is extremely common for wire gauges to be labelled incorrectly, even down to what is printed on your wire. That "18 AWG" pixel wire is more likely to actually be 20 or even 22 AWG. This affects the overall current carrying capacity of the wire.

Wire type - Wire in the actual cables can be anything from copper clad aluminium, to copper clad tin to 100% copper and each type of wire has different current carrying capacities.

Wire distances - The overall distances of the wire used will affect the current carrying capacity. Where possible, always use the shortest possible wire between pixels.

Temperature - Current carrying capacity is affected by the temperature of the wire. Additionally, as pixels increase in temperature when they are running, resistance increases.

Voltage - As voltage goes up, the amount of wattage for the same given cable size will increase. Of course this is a double edge sword - this results in pre-mature damage to the pixels and additional waste heat.

HD Strip - If you are using strip/ribbon, there are Standard (most common) and Heavy Duty strips, check with your vendor for the maximum length of strip before power injection is required.

The only sure way to determine power consumption is to simply measure it. We have a video here that shows how to measure current on your RGB lights:

To get into the ball park, you can use vendor supplied numbers. Each vendor is likely to list their power consumption in different ways, so you'll need to get to some common amount and we recommend watts as a point of measurement. Watts is calculated based on the following formula:

Of course to determine total wattage, you just multiply the watts per pixel, so a 50 count pixel string with 30mA pixels would be 18 Watts or 1.5 amps @ 12 volts.

Gather all this information and put it into your spreadsheet along with the pixel counts.

SELECT THE CONTROLLER(S)

We've arrived at the point that ironicly most people are worried about which often is one of the easier parts (considering the complexity of power calculations) - picking the pixel controller or controllers needed to operate all your pixels.

Let's start with one common issue - power, yes, it seems like we were done with that but there are still a few things to consider. Controllers will be rated in Amp per output and a common amount is around 5 amps. Let's say that you have a string of pixels that you've calculated will require 8 amps - you might go looking for a controller that will handle 8 amps and then wonder why someone doesn't sell one like that - it is for a good reason and it has to do with resistance. Since pixels are small with little tiny circuit boards that have small places to solder small gauge wire to, there is always a limit to how much current can be passed down the common 18-20 AWG wires found in pixels before it just won't go any further. For an example of this, see this video:

What you can see in the video above is - it just doesn't matter how powerful the power supply is or how much power the controller can provide, there is just a limit to how much power you can "push" down a small group of wires. So what do you do about this? This is where power injection comes in and this process is where you bring power from the same power supply that supplies the controller and inject it later down the line in the middle or end of the pixels. Here is an example of what that looks like:

Injecting Power with Pixels

So, this explains why it only partially matters what the output current of your controller is as there is a limit to how much power could even be supplied from the controller to the furthest lights on long strings of lights.

There are just a few areas that you need to know to pick the right controller and they are:

Power per Output - Each controller is going to have a rated amount for how much current can be output over a single connection. Do NOT go by fuse value as the fuse isn't there to "limit" the current, it is there to prevent a short of wiring. In fact, it is highly likely that you could hook up many more amps of lights than the rated output and the fuse will still not blow as a result of the resistance from the wire and lights themselves. When in doubt - pull out a meter and measure it - you might be surprised.

Power per Bank - In a 16 output pixel controller it is common that the controller will be broken, from a power standpoint, into two banks and that those banks are often around 24-30 amps. There is a good reason for this - this also happens to be the standard amount of power of a 350 Watt power supply (12v @ 29 amps). If all the lights connected to both banks are less than the total amount of power supplied by the power supply, a single power supply can then supply both banks of power, otherwise you may need to break the power into two banks with two separate power supplies.

Power per Controller - This is the total power for both banks combined.

Pixels per Output / Controller - Controllers have varying different limits of pixels they can control. Those limits are along a single output, such as 170 pixels or 680 pixels per physical output. So, when you are laying out which strings or runs of pixels need to be connected to a given output on the controller, be aware of power but also be aware of the need to limit the pixel count if the controller isn't able to handle it - or upgrade to a controller that can handle your needed pixel count.

Most other features are going to be pretty common on most pixel controllers, things like protocol support, null pixels and channel configuration. You can find HolidayCoro Pixel controllers here.

SELECT THE SEQUENCING SOFTWARE

This actually is the easiest part since nearly all controllers, including all pixel controllers from HolidayCoro work with all the common sequencing software on the market today - and even many other non-sequencing applications. So, it is a simple matter of picking one that fits your budget, features and comfort level. Here is a list of sequencing applications, plus some various different factors on each one. Please note that a number of items in this chart are based on opinion:

Since most paid vendors have trial editions, this allows you to tinker with the applications and determine if it feels right to you. A big part of selecting a sequencing application will depend on what you are using now, where you like to get your support (phone, forum, Facebook, etc.) and of course your budget.

SELECT THE METHOD OF SEQUENCE GENERATION

There seem to be two camps when it comes to sequencing - there is the "I'll do it myself" and "I'll use pre-sequenced songs". There are pros and cons to each method:

DIY Sequencing

PRO's

Each sequence will reflect your ability, good or bad on how YOU want your display to feel.

You won't have to hunt down sequences or pay for sequences (typically high pixel count sequences run in the $20 to $40 range).

The sequence will be 100% customized to your display and won't need to be "tweaked" to fit your display elements.

CON's

Sequencing can take from hours per minute of music (high quality, hand sequenced) to an hour per song (lower quality, generic, computer sequenced).

You'll need to learn how to use "self sequencing" applications like LightShow Pro, Xlights Nutcracker or SuperStar lights.) Depending on your skill , this can take hours to days.

Purchase Pre-Sequenced Songs

PRO's

If your element (Megatrees are the most common) matches up perfectly to the pixel count in the sequence, it can be truly plug-n-play.

Allows you to use high quality hand-sequenced songs from others with more skill in this area.

Vendors should be able to help you with loading and minor customization of your sequence as part of the cost of the sequence purchase.

CON's

If your element, in particular house outlines, doesn't "match up" to the sequence from the vendor, it can be a lot of work to adjust it to match the channel count and design of your display.

It costs more in initial outlay. Of course this doesn't factor in if you place a cost on your time.

The major issue today with pixels is that baring a few element types like MegaTrees, there is just about zero standardization. So, if you purchase a pre-sequenced song for someone that has a house outline with 500 pixels and your house has 800 pixel on an outline, it can be fairly complicated (depending on the application) to adapt it over to meet your specific needs.

The problem today is that there isn't really a perfect application out there. Even when I started with pixels back in 2010 I could see that the software would always be a problem (see the Death of the Grid article). I must say that while people have made strides in minor improvements and add-ons, we've yet to see the big money project to make a truly well designed sequencing application. But, that said, don't let this sway you, even with the tools today it is possible to make some really amazing displays.

CONCLUSION

While we've tried to boil down the process of designing a pixel based element to as few elements as possible, the process can be a bit daunting for some. Don't worry - start with a single project and we are sure, like nearly all our customers, that you'll be able to be doing better and better projects before you know it!

Have a great season from HolidayCoro.com!

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